Infrastructure Manager: A TOSCA-Based Orchestrator for the Computing Continuum

The edge-to-cloud continuum involves heterogeneous computing resources, including low-power physical devices, Virtual Machines (VMs) in cloud management platforms and serverless computing services based on the FaaS (Functions as a Service) model. This requires novel strategies to describe and efficiently deploy complex applications that execute across the computing continuum. To this end, this paper introduces the developments in the Infrastructure Manager (IM), an open-source TOSCA-based orchestrator to provision and configure virtualized computing resources from a wide range of cloud platforms. By supplementing TOSCA with additional types, the IM can also provision from FaaS platforms across the computing continuum by leveraging public cloud services such as AWS Lambda and on-premises serverless platforms, such as OSCAR. This allows event-driven data-processing applications across multiple computing platforms and architectures. The evolution of the Infrastructure Manager is described to accommodate the definition in TOSCA of complex applications that span across the computing continuum and their automated provisioning and configuration using Infrastructure as Code (IaC) approaches. Its effectiveness is assessed through a real use case involving a machine-learning classifier application for assisting in the early diagnosis of Rheumatic Heart Disease (RHD). The results show that the new developments enable the IM to efficiently deploy complete application architectures described in TOSCA across the computing continuum, from VMs to FaaS services.